Load cell for smart cap

ABSTRACT

A weight sensor assembly including a strain gauge load cell is disclosed. The weight sensor assembly may be used in a smart cap. The weight sensor includes a platform for weighing objects and a load cell. The load cell includes an annular portion, and first and second beams coupled to the platform. Each of the beams includes a first end fixed to the annular portion and a second end that deforms as the platform displaces downward in response to an applied force. One or more strain gauges are mounted on the beams.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/158,378 filed May 7, 2015 and titled “Smart Cap ForMedication Container”, which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

The present disclosure relates generally to smart caps for medicationcontainers, and more particularly, some embodiments relate to smart capsincluding a weight sensor assembly with a strain gauge load cell.

BACKGROUND

Low prescription medication adherence is a major problem in the UnitedStates with annual costs of over 200 billion dollars. Although severalproducts have been marketed for improving adherence, the majority aretoo costly for most patients. Examples of such products are describedbelow.

GlowCap® is a universal bottle cap that provides a series of escalatingaudio and visual alerts to remind patients to take their medication. TheGlowCap® syncs directly through a mobile broadband network using a localhub. If a patient forgets to take a prescribed medication, he or she maybe sent a text message through the mobile network. The GlowCap® haslimited mobility as it only works in the presence of a mobile network ahub, and is carrier specific. Additionally, it needs its own dataconnection and is costly.

The MedMinder™ pillbox is a 28 compartment pillbox with an internalcellular modem. The pillbox compartments may be prefilled by pharmacies.The box provides audio, visual, text message, and email reminders totake medications, and the internal cellular modem communicates with aremote system for medication refill and tracking. Its main shortcomingis the high monthly fee needed to support its cellular data connection.

CleverCap® is a universal bottle cap that is programmed to time releasetablets. Audio, visual, and mobile reminders may be delivered. The mainshort shortcomings of CleverCap® are its large size, price, and lack ofscale.

PharmAssistant is a smart pill container equipped with a Bluetooth radiothat communicates with a patient's smartphone through an app. Duringoperation, the smart pill container must be in proximity to thesmartphone, which, through the app, causes the box to provide audio andvisual reminders to take medication until the box is opened.

SUMMARY

In various embodiments, a smart cap including a weight sensor assemblyis disclosed. The smart cap includes a circuit board electricallycoupled to the weight sensor assembly. The weight sensor assemblyincludes a platform and load cell.

In various implementations, the load cell includes an annular portionand first and second beams extending inward from the annular portion andcoupled to the platform. The beams include a first end fixed to theannular portion; and a second end that deforms as the platform displacesdownward in response to an applied force. In embodiments, one or morestrain gauges may be attached to the beams. For example, one straingauge in compression and one strain gauge in tension may be attached tothe beams.

In various implementations, the diameter of the load cell (i.e., outerdiameter of the annular portion) is at least 100 times greater than thethickness of the load cell. In a particular implementation, the diameterof the load cell is between 30 and 45 millimeters, and each of the firstbeam and the second beam is between 0.2 and 0.3 millimeters thick andbetween 3.5 and 5.5 millimeters wide.

Other features and aspects of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, the featuresin accordance with embodiments of the invention. The summary is notintended to limit the scope of the invention, which is defined solely bythe claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The technology disclosed herein, in accordance with one or moreembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the disclosedtechnology. These drawings are provided to facilitate the reader'sunderstanding of the disclosed technology and shall not be consideredlimiting of the breadth, scope, or applicability thereof. It should benoted that for clarity and ease of illustration these drawings are notnecessarily made to scale.

FIG. 1 illustrates an example wireless communications environment inwhich the disclosed smart cap may be implemented.

FIG. 2A is a diagram illustrating components of a smart cap inaccordance with an example embodiment of the disclosed technology.

FIG. 2B is a block diagram illustrating an example architecture for thecircuitry of the smart cap of FIG. 2A.

FIG. 3 is a block diagram illustrating a computing device, including amedication tracking application that may be used to interact with asmart cap and provide medication tracking in accordance with embodimentsof the disclosed technology.

FIG. 4 is a diagram showing an exploded view of components of a smartcap that uses an example strain gauge load cell to make weightmeasurements of medication units in accordance with embodiments.

FIG. 5 is a diagram showing the partially assembled smart cap of FIG. 4,including an assembled weight sensor, in accordance with embodiments.

FIG. 6 illustrates an exemplary design of a strain gauge load cell inaccordance with embodiments.

FIG. 7 illustrates the load cell of FIG. 6 after the load cells beamsdeform in response to an applied force by a platform.

FIG. 8A is an example model of a weight sensor assembly including aplatform and load cell before displacement of the platform, inaccordance with embodiments.

FIG. 8B is an example model of a weight sensor assembly including aplatform and load cell after displacement of the platform, in accordancewith embodiments.

FIG. 9 illustrates an example computing module that may be used inimplementing features of various embodiments of the disclosedtechnology.

The figures are not intended to be exhaustive or to limit the inventionto the precise form disclosed. It should be understood that theinvention can be practiced with modification and alteration, and thatthe disclosed technology be limited only by the claims and theequivalents thereof.

DETAILED DESCRIPTION

The technology disclosed herein is directed toward a smart cap formedication containers. Some embodiments are directed toward a universalsmart cap that may be fitted on standard, easy-open and childproofmedication containers. In various embodiments, the disclosed smart capwirelessly transmits medication-related information to a computingdevice for further processing, thereby leveraging the computing device'sprocessing power. In various embodiments, this reduces the computingpower needed in the cap and enables a low-cost, portable solution formedication tracking and compliance. In further embodiments, a noveldesign for a strain gauge load cell that may be used in the smart cap isdescribed.

FIG. 1 illustrates an example wireless communications environment inaccordance with an exemplary embodiment. In this environment, a smartcap 100 attached to medication container 110 communicates with acomputing device 200 over a wireless communication link. Although asmartphone is illustrated, computing device 200 may comprise anycomputing device (smartphone, tablet, laptop, smartwatch, desktop, etc.)configured to receive medication-related information from smart cap 100,and one or more processors and memory modules for processing andinteracting with the data collected by smart cap 100. Computing device200 may also provide a graphical user interface (GUI) to performfunctions such as accepting user input and displaying information to theuser.

Information displayed to the user can include, for example, informationabout the prescription associated with the smart cap (e.g., contained inthe container used with the smart cap). This information can includeinformation such as prescribed dosage times, quantities (e.g. number ofpills) and amounts (e.g. milligrams of the dose), whether the patient iscurrent with his or her dosing interval, whether the patient is behindin a dosing interval, the patient's history of taking the medications astracked by the smart cap, doses remaining in the container, refill datesand statuses, and so on. This information can also include generalinformation about the prescription such as, for example, informationabout the prescription, side effects, dosing instructions (e.g. takewith meals), medication warnings, drug interaction precautions, and soon.

Input that can be accepted on the GUI can include inputs such as, forexample, input by the user querying for information on prescription anddosing history, manual input by the user confirming that particular dosewas taken or confirming that a dose was intentionally skipped, and otherlike information the user may enter regarding the prescription in adosing. Additionally, the GUI may provide the user with input to orderrefills, communicate with his or her health care provider, query thesystem for information about the prescription, and so on.

In preferred embodiments, the wireless communication link is a lowenergy communication link such as a radio frequency link based on nearfield communications (NFC), a Bluetooth low energy (LE) link, or aZigBee link. However, in alternative embodiments other wirelesscommunication methods may be used, including those known in the art suchas WiFi, mobile data, and others. In still further embodiments, a wiredcommunication link can be provided between the smart cap 100 andcomputing device 200.

FIG. 2A is a diagram illustrating components of a smart cap 100 inaccordance with an example embodiment. Particularly, this exampleillustrates an exploded view of an example smart cap 100. As illustratedin this example, smart cap 100 includes an enclosure 101 for sealing theopening of medication container 110, a battery 102, circuitry 103, aweight sensor 104, a cap 111, and a cover 105.

As shown, enclosure 101 in this example is configured to provide ahousing for battery 102, circuitry 103 and weight sensor 104. When matedwith cap 111, the combination of enclosure 101 and cover 105 can providea secure and even moisture-proof housing for the components containedtherein. Depending on the application, the housing can be configured toprovide a watertight seal or even a hermetic seal for the componentscontained therein.

As shown in this example, enclosure 101 can be configured to be disposedwithin cover 105. In some embodiments, container 101 is dimensioned suchthat it does not contact the lip of medication container 110. In otherembodiments, it may contact medication container 110. In still furtherembodiments, enclosure 101 may be dimensioned having a diameter suchthat it fits within the mouth of medication container 110.

Spring tabs 112 can be included to releasably mate enclosure 101 and thecomponents contained therein to cover 105. Although spring tabs 112 areillustrated as the attachment mechanism, other attachment devices can beused including, for example, threads or locking tabs. The use of areleasable mating mechanism such as spring tabs 112 allows enclosure 101to be removed from cover 105 to allow access to the components containedtherein. This can be used, for example, to replace battery 102 or any ofthe other components, to electrically connect to the circuitry 103 via awired port, or to otherwise access the contents of enclosure 101.

Although not illustrated in the figure, enclosure 101 can includethreads, tabs or other attachment mechanisms to allow enclosure 101 tobe releasably attached to medication container 110. In otherembodiments, cover 105 can be configured with threads, tabs, or theother attachment mechanisms to allow the cap to be releasably attachedto medication container 110.

Circuitry 103 may include components used to perform the features andfunctions described herein including, for example a microcontroller orother processing system (e.g., having one or more processors orprocessor cores and suitable memory) program to perform these describedfunctions and other functions as would be apparent to one of ordinaryskill in the art upon reading this description.

FIG. 2B is a diagram illustrating an example architecture for suchcircuitry in accordance with one embodiment of the technology disclosedherein. In this example, circuitry includes a processing module 112,which in this example is a single IC microcontroller, indicator devices105, 106, and antenna 108, a wireless communication interface 107, andpower circuitry 113. FIG. 2B also shows how circuitry 103 interfaceswith battery 102, a weight sensor 104 including a low signal amplifier109, and a position sensor 121.

As noted above, in this example processing module 112 is amicrocontroller and can include memory for storing program informationand data and interfaces to allow interfaces to the other components ofthe system. In other embodiments, other processing modules can be usedincluding, for example, ASICs, FPGAs, processor systems using one ormore single or multi-core processors, and so on.

As illustrated in this example, interfaces are provided such thatprocessing module 112 can receive weight signals from weight sensor 104that indicate the weight of the medication container 110 when it ispositioned such that the smart cap 100 bears the entire weight ofmedication container 110. In various embodiments, a position sensor 121(e.g., an accelerometer and/or gyroscope) may provide position signalsto processing module 112 to determine that smart cap 100 is in thecorrect position while weight sensor 104 takes weight measurements. In aparticular implementation, the position sensor 121 is an accelerometerthat detects the relative orientation of smart cap 100 based on theacceleration due to gravity.

In embodiments, the weight signals provided by weight sensor 104 can beamplified, if needed, by a signal amplifier 109 to provide theappropriate signal levels to processing module 112. In embodiments, lowsignal amplifier 109 may be part of weight sensor 104 or circuitry 103.

As described further below, processing module 112 can use the weightinformation contained in the weight signals to determine the weight ofmedication container 110. This information can be used to determine theweight of the contents (i.e. the medicaments) in medication container110. The microcontroller can further be programmed to determine thequantity of medicaments in the medication container 110 based on thecomputed weight of the contents and information about the medicamentscontained in the container such as, for example, medicament andmedicament dosage information. In some implementations of theseembodiments, processing module 112 may first use the position signalsgenerated by position sensor 121 to verify that smart cap 100 was in acorrect position during weight measurement before determining the weightof medication container 110 based on the weight signals.

Information about the medicaments can be preprogrammed by the pharmacywhen the medication container 110 is filled. Alternatively, informationabout the medicaments can be preprogrammed at the factory and the smartcap can be designated for the particular medicaments for which it isprogrammed. In still further embodiments, information about themedicaments can be programmed by the user such as, for example, by thegraphical user interface included with device 200. While in someenvironments it may not be desirable to allow the user to alter themedicament information, in some applications this can be done to allowthe user to repurpose medication container 110 and smart cap 100 forvarious further uses. Because it may be desirable to minimize powerconsumption, and accordingly processing power, these computations can bemade external to the smart cap 100 such as, for example, by device 200.In such embodiments, the weight signals and position signals, orinformation contained in the weight signals and position signals, can betransferred to the external device (e.g. device 200) for computation andreporting to the user.

In the illustrated embodiment, the electrical components are powered bya coin cell battery 102. However, other suitable battery or power supplytechnologies known in the art or later developed may be used. Forexample, piezo or vibration energy harvesters, photovoltaic cells, orother like devices can be used. In some embodiments, the circuitry canbe configured to remain on at all times such that alerts can begenerated, measurements made, and other activities occur in real time asmay be needed depending on the device program. In other embodiments,circuitry can be configured to enter a low-power or sleep mode such thatvarious of the components enter a low-power or inactive mode when thedevice is not in use. For example, processing module 112 can beconfigured to maintain a timer and “wake up” at certain times or atperiodic intervals to measure the quantity of medicaments in thecontainer and to report back to device 200 or to other external systems.In still further embodiments, mechanisms such as, for example, an on/offswitch can be provided to allow the user to manually control the on/offstate of the device. In even further embodiments, devices such as microswitches or gravity switches can be used to determine when the containeris placed with the lid facing down.

In various embodiments, smart cap 100 may include memory, as notedabove, to store computing instructions and to store information that canbe used by the system (processing module 112, device 200, or both). Insome embodiments, sufficient memory is provided to store informationabout the contents of the container and information obtained from one ormore sensors (e.g., weight sensor and position sensor) for transmissionto computing device 200 for processing. This information may include,for example, the name of the drug or drugs in medication container 110,the patient's name, an identification of the patient's computing device,the date and time the container was last opened, the total weight ofmedication units in the container, the current orientation of themedication container 110 and cap 100, and the change in weight ofmedication units since the container was last opened.

In preferred embodiments, smart cap 100 transmits information to andreceives information from computing device 200 using an RFID orBluetooth LE connection. In one such embodiment, information may betransmitted and optionally received by smart cap 100 using a RFID NFCtag or other NFC device 107. An example NFC device 107 can includesingle or bidirectional communication for NFC applications and canfurther be enabled by placing it within close proximity of or touching acompatible NFC or RFID equipped computing device 200. As an example, theinformation transmitted by smart cap 100 may include the date and timethe container was last opened, the current position of smart cap 100,and the change in weight of medication units since the container waslast opened. As another example, the information received by smart cap100 may include updated patient information, updated medicationinformation, or an instruction to unlock the smart cap.

As another example, smart cap 100 can transmit an alert to device 200 ifthe container remains unopened and the weight of the container has notchanged within a predetermined time after a scheduled dosing time. Insuch an example, processing module 112 can include enough processingpower and program instructions to enable processing module 112 to detectthe current time, determine the open/close state of the container,determine the weight of the contents in the container, and determinewhether the information indicates that the patient failed to take aprescribed dose at the prescribed dosing time. As yet another example,smart cap 100 can transmit an alarm to device 200, based on the signalsgenerated by position sensor 121, if the container is not in a correctposition to measure weight.

In other embodiments, processing module 112 can simply gatherinformation about the state of the container (e.g., weight signals,position signals, the open/close state, and other data) and provide thisinformation to device 200 to perform the computation and generate thealarm if necessary. In such embodiments where processing module 112gathers data and transmits the data to device 200 for processing, asopposed to performing the processing computations itself, circuitry 103can be implemented at a lower cost and it can consume less power.

In various embodiments, information may be communicated by initiating ahandshaking procedure between smart cap 100 and computing device 200 atpredetermined times or predetermined periodic intervals (e.g., a fewtimes per day to conserve battery life). In these embodiments, thehandshaking procedure may be initiated by smart cap 100 or computingdevice 200. In further embodiments, smart cap 100 may include a buttonto mute the handshake function, thereby conserving the battery life ofbattery 102.

Prior to use, a pharmacist or patient may program the cap with dataincluding a medication identification, patient name, dosage quantitiesand times, warnings, any special instructions, and other informationthat may be useful to the patient or to the processing system. Inembodiments, further described below, this data may be programmed usinga medication tracking application (app) installed on computing device200.

Also illustrated in the example of FIG. 2B are user alert mechanisms,which in this example include an LED 105 and a buzzer 106. Accordingly,processing module 112 can be configured to trigger an alert via anaudible alert mechanism, a tactile alert mechanism, or a visual alertmechanism, or a combination of the foregoing. For example, the systemcan be configured to provide a particular alert at the dosing time andanother alert if the device determines that the patient missed a dose.Further, an alert can be provided before the dosing time to alert thepatient that the dosing time is approaching. The alerts can be differentto differentiate amongst these different occurrences such as, forexample, by using different color LEDs, a different sequence of flashingindicators, different sounds or tones, and so on.

In further embodiments, circuitry 103 can be configured to provideescalating visual and audio reminders to the patient to, for example,warn the patient of an upcoming dosage time, and alert the patient if adosage time has passed. For example, when it is time to consumemedication, LED 105 may flash and buzzer 106 may sound an alarm for apredetermined period of time. After a patient removes smart cap 100 andconsumes one or more medication units, smart cap 100 may store thedate/time of consumption, the ID of the computing device 200 it lastcommunicated with, and the change in weight of the medication unitsmeasured using weight sensor 104. If it is determined (e.g., byprocessor module 112 or smart device 200) that the patient did notconsume the appropriate quantity of medication units, did not consumeany medication units at the predetermined time, or did not remove smartcap 100, another alert can be provided.

In embodiments, smart cap 100 may include a locking mechanism that maybe unlocked using a medication tracking application installed oncomputing device 200. For example, device 200 can send an unlock signalto circuitry 103 to unlock smart cap 100, thereby allowing medicationcontainer 110 to be opened. In some embodiments, device 200 can beconfigured to wirelessly transmit an unlock signal (or a lock signal tolock the container) to circuitry 103. In embodiments where the computingdevice 200 includes NFC capabilities, smart cap 100 may be unlocked bybringing smart cap 100 into close proximity with device 200.

Computing device 200 can be configured to require a password, PIN, orother security code before sending a signal to unlock the container.This can provide a measure of security to the container and may alsoprovide a child-safe container. In embodiments, computing device 200 mayinterface with multiple containers. In these embodiments, mechanisms maybe provided via the medication tracking application to allow the useridentify which containers should be opened or unlocked. In furtherembodiments, the system can be configured to automatically identify thecontainers to be unlocked based on the dosing times of the medicamentscontained in the medication containers. Where multiple users are usingdevice 200 to access their respective medication containers, user IDscan be used to differentiate amongst the users who have access to theparticular containers.

In single-user embodiments, smart cap 100 may record the ID of thecomputing device 200 used to unlock smart cap 100, thereby providing anidentification of the person that accessed the medication. In single-ormulti-user embodiments, smart cap 100 may record the ID of the user whoaccessed computing device 200 to unlock smart cap 100.

As noted above, one or more wired or wireless communication interfacescan be included to allow smart cap 100 to interface with device 200. Asshown in the example of FIG. 2B, circuitry 103 can include a near fieldcommunication device 107 or antenna 108 for non-NFC communications. Inthe illustrated example, antenna 108 is a surface mount technology (SMT)antenna that can be directly mounted to a printed circuit board on whichother components of circuitry 103 are also mounted. Also in theillustrated example, NFC device 107 includes an NFC IC 107A and an NFCantenna 107B.

In one particular embodiment, circuitry 103 may be implemented as anRFID tag that is active or battery-assisted passive. In this embodiment,the RFID tag may include an RF antenna for receiving and transmittingsignals, an integrated circuit for storing and processingmedication-related information, modulating and demodulating RF signals,and a power source. The RFID tag may include fixed or programmable logicfor processing medication-related information. Additionally, the RFIDtag storage may be read-write, read-only, or write once, read many(WORM). In implementations where the RFID tag is an active RFID tag, itmay broadcast an RF signal including its ID signal and/ormedication-related information at predetermined times or predeterminedperiodic intervals (e.g, a few times per day to conserve battery life).

In another embodiment, circuitry 103 may be implemented as a passiveRFID tag without its own power source. For example, the RFID tag may bea near field communication (NFC) tag that is powered by anelectromagnetic field produced by an active NFC component in closeproximity such as an active NFC component of computing device 200. Whilepowered by an active NFC component, the passive NFC tag may read andwrite medication information to memory, transmit information tocomputing device 200, and optionally receive information from computingdevice 200. Such an exchange of information may be directed, forexample, by a GUI of computing device 200 that instructs a patient tobring computing device 200 in close proximity to smart cap 100 when itis time to take medication.

As one having skill in the art would appreciate from the abovedescription, smart cap 100 in various embodiments may be configured toprovide a low-cost, portable solution for medication tracking andcompliance. In some embodiments this can be accomplished by leveragingthe processing power of computing device 200 to provide medicationtracking. FIG. 3 is a block diagram illustrating example components ofone such computing device 200.

As illustrated in this example, computing device 200 comprises aconnectivity interface 201, storage 202 with medication trackingapplication 210, processor 204, a graphical user interface (GUI) 205including display 206, and a bus 207 for transferring data between thevarious components of computing device 200. In preferred embodiments,connectivity interface 201 connects computing device 200 to smart cap100 through radio frequency communication (e.g., using NFCcommunication) or using Bluetooth LE communications. In alternativeembodiments, connectivity interface 201 may communicate with smart cap100 using Wi-Fi, a ZigBee network, a wireless local area network, acellular network, or the like.

Storage 202 may comprise volatile memory (e.g. RAM), non-volatile memory(e.g. flash storage), or some combination thereof. In variousembodiments, storage 202 may store medication tracking informationreceived from smart cap 100. Additionally, storage 202 may store amedication tracking application 210, that when executed by processor204, allows a patient to monitor their medication compliance history,receive medication reminders, process medication information receivedfrom smart cap 100, and transmit information to smart cap 100.

In various embodiments, a user may interact with activity trackingapplication 210 via a GUI 205 including a display 206, such as, forexample, a touchscreen display that accepts various hand gestures asinputs. GUI 205 can also include a keypad, a microphone, or other inputadvices to accept additional forms of input from the user. In accordancewith various embodiments, activity tracking application 210 may processmedication information received from smart cap 100, transmit informationto smart cap 100, allow a patient to interact with smart cap 100, andotherwise display information related to the patient's consumption ofmedication such as reports of the patient's compliance, the time of thenext scheduled dosage, the number of medication units remaining in themedication container, the medication being taken, contact informationfor the pharmacy or prescribing doctor, drug interaction precautioninformation and other information.

For example, in one embodiment activity tracking application 210 maygenerate medication compliance alarms that notify the user whenmedications need to be taken by causing computing device 200 to displayvisual notifications and output audio notifications. In furtherembodiments, medication compliance alarms can further include othermessages or alerts to the patient such as, for example, text messages toa device identified by the patient, alerts to a smart bracelet or otheralert monitoring device worn by or kept in proximity with the patient.In implementations where computing device 200 includes an NFC module,the medication compliance alarms may be turned off by placing device 200in close proximity to cap 100 (e.g., by touching the medicationcontainer with device 200). In such implementations, this action mayadditionally disable any medication compliance alarms generated by smartcap 100 as described above.

In another embodiment, activity tracking application 210 may help apatient locate a lost medication container. For example, a patient mayuse activity tracking application 210 to transmit a beacon fromcomputing device 200 to smart cap 100 to locate smart cap 100. Inresponse to the beacon, smart cap 100 may, for example, emit an audiblealarm and/or flash an LED.

In embodiments, activity tracking application 210 may dynamically sharemedication related data with one or more secure servers including EMRdatabases and pharmacy databases such that medication related data isaccessible by parties of interest including, for example, the patient, adoctor, the patient's caregiver, and pharmacies. In this manner, thepatient's medication adherence may be improved, and doctors and EMRs maybetter treat the patient based on the patient's medication history.

In further embodiments, activity tracking application 210 may determinethe number of medication units remaining in the medication containerbased on the weight information received from smart cap 100. In one suchimplementation, the remaining number of medication units may bedetermined by dividing the last recorded total weight of medicationunits by the known weight of each of the medication units. In anotherimplementation, the remaining number of medication units may bedetermined by dividing the last recorded total weight of medicationunits by the last recorded change in weight of medication units afterremoving one or more units. The system can be programmed with the weightof the medication container and the portion of the smart cap supportedby the weight sensor, so that this weight can be taken into account whendetermining the number of medication units remaining in the medicationcontainer. In other words, the weight of the medication container andportion of the cap supported by the weight sensor can be subtracted fromthe total weight to determine the weight of the medication unitsremaining in the container. In yet another implementation, the remainingnumber of medication units may be determined by tracking the totalnumber of medication units, and deducting from this total each time aunit is removed based on a change in weight after the cap is removed.

As discussed above, the disclosed smart cap in various embodiments mayinclude a weight sensor configured to provide absolute weightmeasurements, differential weight measurements, or both absolute anddifferential weight measurements of medication units in the medicationcontainer. Using these measurements, the number of medication unitsstored within the medication container may be determined and dynamicallyupdated (e.g. using activity tracking application 210). Although weightsensor 104 is illustrated as a full bridge resistance sensor, otherweight sensors, further described below, may be used. Although describedas a weight sensor for simplicity, it should be noted that the weightsensor may alternatively or additionally function as a mass sensor thatprovides differential mass measurements and/or absolute massmeasurements. In these implementations, a fixed gravity constant (e.g.,standard acceleration due to gravity) or acceleration due to gravitydetector can be used to convert the measured weight to mass.

In a first embodiment, the weight sensor measures changes in weight bydetermining the change in electrical resistance of a conductor loadplate under pressure. In various implementations of this embodiment, theweight sensor may be implemented as a strain gauge, including straingauge load cells and resistive wire that are connected to a load platein various configurations such as, for example, a spiral pattern, azigzag pattern, etc.

As pressure on the load plate increases or decreases by adding orremoving medication units, the load plate displaces a distancecorresponding to the pressure, thereby reducing or increasing theconductor's cross-sectional area. In other words, the strain(deformation due to applied pressure) on the conductor changes inresponse to changes in load pressure, or weight. A reduction in thecross sectional area of the conductor will increase electricalresistance. Conversely, an increase in the cross-sectional area of theconductor will decrease resistance. In various implementations, thechange in resistance may be measured using one or more resistancedetection circuits such as, for example, Wheatstone bridges,differential amplifiers, instrumentation amplifiers, and other toolsknown to those having skill in the art.

In a second embodiment, the weight sensor is a piezo-based weight sensorthat functions by measuring the change in capacitance of a piezoelectriccrystal under pressure. In various implementations of these embodiments,a piezocrystal is disposed between two conductive electrodes, where oneof the electrodes is fixed while the other is mechanically connected toa load plate or acts as the load plate itself.

As medication units are added, the pressure on the load plate increasesand the load place is displaced by a corresponding amount that causescompression of the piezoelectric crystal. This compression decreases thephysical distance between the plates, which causes a change in theoverall capacitance value of the crystal sensor that can be measured.Several methods may be used to measure this change in capacitance suchas, for example, methods using AC Wheatstone bridges, charge anddischarge timing, and other methods known to those having skill in theart.

In a third embodiment, the weight sensor is a quantum tunneling compound(QTC) sensor that functions by measuring the change in resistance of aQTC material under pressure. In various implementations, sheets of QTCmaterial, QTC pills, or QTC cable may be employed in the weight sensor.In yet further implementations, other QTC configurations may beemployed.

In one example implementation, a QTC sheet is positioned between twoelectrodes and a load plate mechanically attached to one of theelectrodes. As medication units are added to the medication container,the pressure on the load plate increases, causing it to displace by acorresponding amount. Subsequently, the quantum tunneling effect of theQTC substance will increase, causing an increase in current flow. Invarious implementations, the change in current flow may be measuredusing one or more of differential amplifiers, instrumentationamplifiers, and other tools known to those having skill in the art.

In a fourth embodiment, the weight sensor is a capacitance-based weightsensor that functions by measuring the change in capacitance between twoconductive plates that are physically separated. In variousimplementations of this embodiment, the weight sensor includes twoconductive electrodes spaced by a dielectric or air, whereby one of theelectrodes is fixed and the other electrode is mechanically coupled to aload plate or acts as a load plate. As medication units are added to themedication container, the pressure on the load plate increases, causingit to displace by a corresponding amount, thereby causing the load plateelectrode to compress and distort. As this compression decreases thephysical distance between the plates, the capacitance changes. Thereduction in distance reduces the overall capacitance of the sensor andcan be measured using various methods such as methods that use ACWheatstone bridges, charge timing, discharge timing, and other methodsknown to those having skill in the art.

In a fifth embodiment, the weight sensor is an inductance-based weightsensor that functions by measuring the change in inductance of aninductor. In various implementations of this embodiment, a spring-typeinductor placed under pressure or a ferrous core going into or out of aninductor may be used. Generally, the inductor will be connected to aload plate.

As medication units are added to the medication container, the pressureon the load plate increases, causing it to deflect by a correspondingamount that causes the load plate to compress and distort. Thiscompression of the inductor causes a change in the inductance, which maybe measured to determine the weight of the medication units in themedication container. The change in inductance may be measured usingvarious methods such as methods that use AC Wheatstone bridges, chargetiming, discharge timing, and other methods known to those having skillin the art.

Because high humidity can cause moisture vapor to be absorbed by manysubstances, this may influence the measured weight of the medicationunits. Accordingly, in further embodiments of the smart cap's weightmeasuring apparatus, the humidity of the medication container, externalenvironment, or both may be accounted for in determining the number ofmedication units in the container. In one such example, one or morehumidity sensors in the smart cap or medications container may measurethe humidity to compensate for weight measurement errors due tohumidity, or due to humidity levels over time. In yet furtherembodiments, a temperature sensor may measure temperature and compensatefor temperature-induced changes in weight using techniques known tothose having skill in the art.

FIG. 4 is a diagram showing an exploded view of components of a smartcap 300 that uses an example strain gauge load cell to make weightmeasurements of medication units in accordance with embodiments. Smartcap assembly 300 includes an enclosure and cover 310, a platform 320 forplacing medication units, a support ring 330, a load cell 340, a support350, a printed circuit board 360, and a cap 370. FIG. 4 is described inconjunction with FIG. 5, which is a diagram showing a partiallyassembled smart cap, including an assembled weight sensor, includingstrain gauges 342 electrically coupled to printed circuit board 360.

During weight measuring operations, a user may place the smart capupside down (i.e., with cap 370 facing down) on a surface and mountmedication units on platform 320. As pressure on platform 320 increases,platform 320 displaces downward and pushes on load cell 340, which, asfurther described below, causes deformation of beams or spring elementson load cell 340. Strain gauges 342 mounted on the beams of load cell340 measure the distortion or strain on the beams, and output electricalsignals that may be used to determine the total load or weight of themedication units based on the measured strain.

Strain gauges 342 include at least one strain gauge that measures strain(i.e., elongation or contraction) as a change in electrical resistancecaused by tension or compression of the beams of the load cell, andpreferably, at least one strain gauge that is in tension and one straingauge that is in compression. For example, strain gauges 342 may bearranged in a quarter bridge configuration, half bridge configuration,or Wheatstone bridge configuration.

In the particular example of FIG. 5, load cell 340 is mounted with twostrain gauges on a top surface of its beams (e.g., in tension) and withtwo strain gauges (not shown) on an opposite bottom surface of the beam(e.g., in compression). These four strain gauges may form a Wheatstonebridge that maximizes the sensitivity of the load cell. As would beappreciated by one having skill in the art, load cell 340 may be mountedwith any number of strain gauges subject to the available mounting spaceon load cell 340.

FIG. 6 illustrates an exemplary double cantilever beam design for a loadcell 340 in accordance with embodiments. In various implementations,load cell 340 may be dimensioned to fit in a smart cap or other devicehaving a circular housing. As shown in this embodiment, load cell 340includes a ring or annular portion 348, two parallel spring elements orbeams 342 and 343 extending inward from annular portion 348, and acenter connecting beam 344 that couples beam 342 and 343. Inembodiments, load cell 340 may have an outer diameter of less than 45millimeters (e.g., 38.1 millimeters) and may comprise a suitable metalor other material (e.g., aluminum) that may be made stiff in an off-axisdirection of load cell 340. In embodiments, load cell 340 is made of aflat piece of material (e.g., aluminum) having an outer diameter (i.e.,outer diameter of annular portion 348) that is at least two orders ofmagnitude greater than its thickness. In particular embodiments, loadcell 340 has an outer diameter of between 30 and 45 millimeters.

Annular portion 348 may provide structural integrity to load cell 340and comprises a plurality of holes 345 for mounting load cell 340 tosupport ring 330 using a suitable fastening mechanism (e.g., screws,pins, nails, etc.). Alternatively, in other embodiments, annular portion348 may be attached to support ring 330 using other suitable attachmentmeans, such as, for example, by gluing or welding.

In this embodiment, outer beams 342-343 are fixed to annular portion 348on one end and coupled by a center connecting beam 344 on the other end.Beams 342-343 and 344 include a plurality of holes 346 for mounting andfixing load cell beams 342-343 and 344 to platform 320 using a suitableattachment mechanism (e.g., screws, pins, nails, etc.). In embodiments,mounting holes 346 may be placed in a configuration that provides lineartravel up and down and prevents tilting of platform 320 as it displacesfrom the weight of medication units.

As illustrated in the above embodiments, center connecting beam 344keeps the distance between beams 342 and 343 fixed relative to eachother as beams 342 and 343 deform in response to pressure from thedisplacing platform 320. In alternative embodiments, center connectingbeam 344 may be omitted and beams 342 and 343 may each have one endfixed to annular portion 348 and another end floating over the centeraperture of load cell 340.

During construction of the weight sensor, at least one strain gauge maybe mounted and bonded on each deforming beam 342-343 of load cell 340.For example, as illustrated by the implementation of FIG. 5, a straingauge in tension may be mounted on a top surface of each beam 342-343,and a strain gauge in compression may be mounted on the bottom surfaceof each beam 342-343.

The thickness of beams 342 and 343, in various embodiments, is at leastten times less than the width of the beams, and least one hundred timesgreater than the diameter of load cell 340. For example, in particularembodiments, beams 342 and 343 may be between 0.2 and 0.3 millimetersthick and between 3.5 and 5.5 millimeters wide. In particularembodiments, center connecting beam 344 may be between 3.0 and 4.5millimeters wide. This flat beam design may help increase the amount ofdeflection experienced by beams 342-343 under deflection by platform320, thereby increasing the measured beam strain by the strain gauges.Such a design may be particularly helpful for measuring small changes inweight (e.g., medication units weighing 1 to 10 mg).

As decreasing the thickness of beams 342 and 343 may increase theoff-center or off-axis sensitivity (i.e., measurement error) of the loadcell, particularly when weight is loaded on the edge of platform 320, invarious embodiments beams 342 and 343 may be made stiff in the off-axisdirection. For example, the beam may be 100 times stiffer in theoff-axis direction relative to the on-axis direction. Accordingly, themeasurement error of the signal output by the strain gauges may be 100times less than the signal itself. For example, if a 10 mg pill isweighed, the error would be about 0.1 mg or less. In particularembodiments, the off-axis spring constant of beams 342-343 may bebetween 150 and 300 N/m.

As platform 320 displaces downward, beams 342-343 deform along the endsthat are not fixed to annular portion 348. FIG. 7 illustrates deformedbeams 342 and 343 in accordance with an embodiment. The illustrated twobeam design, with one side of each beam fixed to annular portion 348,and the other side coupled to center beam 344, may act as a Robervalmechanism that prevents tilting of platform 320 as it pushes downward onload cell 340. For example, if a user of the smart cap places medicationunits on the edge of platform 320 as opposed to its center, the platform320 may still travel downward in a linear direction without anynoticeable tilt.

FIGS. 8A-8B illustrate an example model of a weight sensor assemblyincluding a platform 320 and load cell 340, before and after thedownward displacement of platform 320. As shown in FIG. 8B, the doublecantilever beam design of load cell 340 allows platform 320 to traveldownward in an approximately linear direction without any perceptibletilt.

Although load cell 340 has been described above with reference to anexample double cantilever beam design, load cell 340 need not be limitedto this precise configuration in accordance with embodiments of thetechnology disclosed herein. For example, the beams need not necessarilyextend at right angles from the annular portion. Additionally, adifferent number of beams or configuration of beams may be used. Forexample, the beams (e.g., three beams) may be arranged in a spiralconfiguration with the platform attached to the center of the load cell.

FIG. 9 illustrates an example computing module that may be used inimplementing features of various embodiments of the disclosedtechnology. As used herein, the term module might describe a given unitof functionality that can be performed in accordance with one or moreembodiments of the present application. As used herein, a module mightbe implemented utilizing any form of hardware, software, or acombination thereof. For example, one or more processors, controllers,ASICs, PLAs, PALs, CPLDs, FPGAs, logical components, software routinesor other mechanisms might be implemented to make up a module. Inimplementation, the various modules described herein might beimplemented as discrete modules or the functions and features describedcan be shared in part or in total among one or more modules. In otherwords, as would be apparent to one of ordinary skill in the art afterreading this description, the various features and functionalitydescribed herein may be implemented in any given application and can beimplemented in one or more separate or shared modules in variouscombinations and permutations. Even though various features or elementsof functionality may be individually described or claimed as separatemodules, one of ordinary skill in the art will understand that thesefeatures and functionality can be shared among one or more commonsoftware and hardware elements, and such description shall not requireor imply that separate hardware or software components are used toimplement such features or functionality.

Where components or modules of the application are implemented in wholeor in part using software, in one embodiment, these software elementscan be implemented to operate with a computing or processing modulecapable of carrying out the functionality described with respectthereto. One such example computing module is shown in FIG. 9. Variousembodiments are described in terms of this example-computing module1200. After reading this description, it will become apparent to aperson skilled in the relevant art how to implement the applicationusing other computing modules or architectures.

Referring now to FIG. 9, computing module 1200 may represent, forexample, computing or processing capabilities found within desktop,laptop, notebook, and tablet computers; hand-held computing devices(tablets, PDA's, smart phones, cell phones, palmtops, etc.); wearablecomputing devices such as smartwatches; mainframes, supercomputers,workstations or servers; or any other type of special-purpose orgeneral-purpose computing devices as may be desirable or appropriate fora given application or environment. Computing module 1200 might alsorepresent computing capabilities embedded within or otherwise availableto a given device. For example, a computing module might be found inother electronic devices such as, for example, digital cameras,navigation systems, cellular telephones, portable computing devices,modems, routers, WAPs, terminals and other electronic devices that mightinclude some form of processing capability.

Computing module 1200 might include, for example, one or moreprocessors, controllers, control modules, or other processing devices,such as a processor 1204. Processor 1204 might be implemented using ageneral-purpose or special-purpose processing engine such as, forexample, a microprocessor, controller, or other control logic. In theillustrated example, processor 1204 is connected to a bus 1202, althoughany communication medium can be used to facilitate interaction withother components of computing module 1200 or to communicate externally.

Computing module 1200 might also include one or more memory modules,simply referred to herein as main memory 1208. For example, preferablyrandom access memory (RAM) or other dynamic memory, might be used forstoring information and instructions to be executed by processor 1204.Main memory 1208 might also be used for storing temporary variables orother intermediate information during execution of instructions to beexecuted by processor 1204. Computing module 1200 might likewise includea read only memory (“ROM”) or other static storage device coupled to bus1202 for storing static information and instructions for processor 1204.

The computing module 1200 might also include one or more various formsof information storage mechanism 1210, which might include, for example,a media drive 1212 and a storage unit interface 1220. The media drive1212 might include a drive or other mechanism to support fixed orremovable storage media 1214. For example, a hard disk drive, a solidstate drive, a magnetic tape drive, an optical disk drive, a CD, DVD, orBlu-ray drive (R or RW), or other removable or fixed media drive mightbe provided. Accordingly, storage media 1214 might include, for example,a hard disk, a solid state drive, magnetic tape, cartridge, opticaldisk, a CD, DVD, Blu-ray or other fixed or removable medium that is readby, written to or accessed by media drive 1212. As these examplesillustrate, the storage media 1214 can include a computer usable storagemedium having stored therein computer software or data.

In alternative embodiments, information storage mechanism 1210 mightinclude other similar instrumentalities for allowing computer programsor other instructions or data to be loaded into computing module 1200.Such instrumentalities might include, for example, a fixed or removablestorage unit 1222 and an interface 1220. Examples of such storage units1222 and interfaces 1220 can include a program cartridge and cartridgeinterface, a removable memory (for example, a flash memory or otherremovable memory module) and memory slot, a PCMCIA slot and card, andother fixed or removable storage units 1222 and interfaces 1220 thatallow software and data to be transferred from the storage unit 1222 tocomputing module 1200.

Computing module 1200 might also include a communications interface1224. Communications interface 1224 might be used to allow software anddata to be transferred between computing module 1200 and externaldevices. Examples of communications interface 1224 might include a modemor softmodem, a network interface (such as an Ethernet, networkinterface card, WiMedia, IEEE 802.XX or other interface), acommunications port (such as for example, a USB port, IR port, RS232port Bluetooth® interface, or other port), or other communicationsinterface. Software and data transferred via communications interface1224 might typically be carried on signals, which can be electronic,electromagnetic (which includes optical) or other signals capable ofbeing exchanged by a given communications interface 1224. These signalsmight be provided to communications interface 1224 via a channel 1228.This channel 1228 might carry signals and might be implemented using awired or wireless communication medium. Some examples of a channel mightinclude a phone line, a cellular link, an RF link, an optical link, anetwork interface, a local or wide area network, and other wired orwireless communications channels.

In this document, the terms “computer program medium” and “computerusable medium” are used to generally refer to transitory ornon-transitory media such as, for example, memory 1208, storage unit1220, media 1214, and channel 1228. These and other various forms ofcomputer program media or computer usable media may be involved incarrying one or more sequences of one or more instructions to aprocessing device for execution. Such instructions embodied on themedium, are generally referred to as “computer program code” or a“computer program product” (which may be grouped in the form of computerprograms or other groupings). When executed, such instructions mightenable the computing module 1200 to perform features or functions of thepresent application as discussed herein.

Although described above in terms of various exemplary embodiments andimplementations, it should be understood that the various features,aspects and functionality described in one or more of the individualembodiments are not limited in their applicability to the particularembodiment with which they are described, but instead can be applied,alone or in various combinations, to one or more of the otherembodiments of the application, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentapplication should not be limited by any of the above-describedexemplary embodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. The use of theterm “module” does not imply that the components or functionalitydescribed or claimed as part of the module are all configured in acommon package. Indeed, any or all of the various components of amodule, whether control logic or other components, can be combined in asingle package or separately maintained and can further be distributedin multiple groupings or packages or across multiple locations.

Additionally, the various embodiments set forth herein are described interms of exemplary block diagrams, flow charts and other illustrations.As will become apparent to one of ordinary skill in the art afterreading this document, the illustrated embodiments and their variousalternatives can be implemented without confinement to the illustratedexamples. For example, block diagrams and their accompanying descriptionshould not be construed as mandating a particular architecture orconfiguration.

While various embodiments of the present disclosure have been describedabove, it should be understood that they have been presented by way ofexample only, and not of limitation. Likewise, the various diagrams maydepict an example architectural or other configuration for thedisclosure, which is done to aid in understanding the features andfunctionality that can be included in the disclosure. The disclosure isnot restricted to the illustrated example architectures orconfigurations, but the desired features can be implemented using avariety of alternative architectures and configurations. Indeed, it willbe apparent to one of skill in the art how alternative functional,logical or physical partitioning and configurations can be implementedto implement the desired features of the present disclosure. Also, amultitude of different constituent module names other than thosedepicted herein can be applied to the various partitions. Additionally,with regard to flow diagrams, operational descriptions and methodclaims, the order in which the steps are presented herein shall notmandate that various embodiments be implemented to perform the recitedfunctionality in the same order unless the context dictates otherwise.

What is claimed is:
 1. A weight sensor assembly, comprising: a platform;and a load cell, comprising: an annular portion; a first beam and asecond beam coupled to the platform, wherein each of the beamscomprises: a first end fixed to the annular portion; and a second endthat deforms as the platform displaces downward in response to anapplied force; and a first strain gauge mounted on the first beam and asecond strain gauge mounted on the second beam.
 2. The weight sensorassembly of claim 1, wherein the diameter of the load cell is less than45 millimeters.
 3. The weight sensor assembly of claim 2, wherein thediameter of the load cell is at least 100 times greater than thethickness of the load cell.
 4. The weight sensor assembly of claim 2,wherein the diameter of the load cell is at least 100 times greater thanthe thickness of the beams of the load cell.
 5. The weight sensorassembly of claim 4, wherein each of the first beam and the second beamis between 0.2 and 0.3 millimeters thick and between 3.5 and 5.5millimeters wide.
 6. The weight sensor assembly of claim 2, furthercomprising: a third strain gauge mounted on the first beam on a surfaceopposite the first strain gauge, and a fourth strain gauge mounted onthe second beam on a surface opposite the second strain gauge.
 7. Theweight sensor assembly of claim 2, further comprising: a support ring,wherein the annular portion is directly coupled to the support ring. 8.The weight sensor of claim 2, further comprising: a center connectingbeam, the center connecting beam, comprising: a first end coupled to thesecond end of the first beam; and a second end coupled to the second endof the second beam, wherein the center connecting beam keeps thedistance between the first beam and the second beam fixed as the firstbeam and the second beam deform as the platform displaces downward.
 9. Aload cell for a strain gauge weight sensor, the load cell comprising: anannular portion; a first beam and a second beam extending inward fromthe annular portion, wherein each of the beams comprises: a first endfixed to the annular portion; and a second end that deforms in responseto a load force applied to the beams.
 10. The load cell claim 9, whereinthe diameter of the load cell is less than 45 millimeters.
 11. The loadcell of claim 10, wherein the diameter of the load cell is at least 100times greater than the thickness of the load cell.
 12. The load cell ofclaim 10, wherein the diameter of the load cell is at least 100 timesgreater than the thickness of the beams of the load cell.
 13. The loadcell of claim 12, wherein each of the first beam and the second beam isbetween 0.2 and 0.3 millimeters thick and between 3.5 and 5.5millimeters wide.
 14. The load cell of claim 10, wherein the first beamand the second beam each comprise apertures for directly coupling thebeam to a platform of a weight sensor.
 15. The load cell of claim 14,further comprising: a center connecting beam, the center connectingbeam, comprising: a first end coupled to the second end of the firstbeam; and a second end coupled to the second end of the second beam,wherein the center connecting beam keeps the distance between the firstbeam and the second beam fixed as the first beam and the second beamdeform in response to a load force applied to the beams.
 16. The loadcell of claim 10, wherein each of the first and second beams is at least100 times stiffer in the off-axis direction relative to the on-axisdirection.
 17. A cap, comprising: a circuit board; a weight sensorassembly, comprising: a platform; and a load cell, comprising: anannular portion; a beam coupled to the platform, wherein the beamcomprises a first end fixed to the annular portion and a second end thatdeforms as the platform displaces downward in response to an appliedforce; and a strain gauge mounted on the beam, wherein the strain gaugeis electrically coupled to the circuit board.
 18. The cap of claim 17,wherein the load cell further comprises: a second beam coupled to theplatform, wherein the second beam comprises a first end fixed to theannular portion and a second end that deforms as the platform displacesdownward in response to an applied force.
 19. The cap of claim 18,wherein the weight sensor assembly further comprises a second straingauge mounted on the second beam, wherein the second strain gauge iselectrically coupled to the circuit board.
 20. The cap of claim 17,further comprising: an enclosure, wherein the enclosure houses thecircuit board and the weight sensor assembly.